1. Field of the Invention
The present invention relates to an ink cartridge that contains ink.
2. Description of the Related Art
Ink cartridges that are generally known comprise an ink bag that contains ink in its interior, a plug for extracting the contained ink from the ink bag, and a rectangular parallelepiped-shaped plastic case configured to house the ink bag.
The ink cartridge of the above-described prior art reference is provided with an opening on the housing. A needle that pierces into the rubber stopper of the plug and introduces the ink within the reservoir portion passes through the opening. While the plug can be visually checked from this opening, visually checking the volume of ink within the reservoir portion is difficult.
One possible approach is to make the moving member capable of rotation around the axis contact a lateral surface of the bag-shaped reservoir portion in the thickness direction, for example, and display the volume of ink within the reservoir portion by the movement of the moving member.
Nevertheless, in such a case, a structure that rotatably supports the axis of the moving member must be provided within the interior of the housing that is substantially box-like in shape. At this time, the structure must be assembled so that the moving member is rotatable with respect to the housing, which is originally a separate member. Further, after such assembly, the moving member must be made to not disengage from the housing. With normal axially supported structures, improving the assemble-ability of a moving member is difficult, resulting in the possibility of a decrease in the productivity of the ink cartridge.